This Halloween night, mostly tricks were being handed out to broadcast primetime, as Supernatural was the only show to enjoy a week-to-week gain.

The CW drama drew 2.1 million total viewers and a 0.9 rating, rising 13 and 29 percent. Leading into that, Arrow (3.35 mil/1.0) was steady in total audience but dipped a tenth to a ratings low to date.

NBC’s 30 Rock, slipping in an election-themed outing on a special night, saw a season high in viewers (with 3.6 mil) and matched what Animal Practice last did in the Wednesdays-at-8 slot.

The X Factor kicked off its live shows with 7.4 mil and a 2.7 — down 23 percent from its last regularly scheduled Wednesday broadcast, but keep in mind, this installment was kinda thrown into Fox’s line-up without much notice (so some cable guides didn’t update, yada yada…).

UPDATE: In one late-night TV headline, David Letterman’s rare talk-show visit to Jimmy Kimmel Live gave the ABC show its largest Wednesday audience in its 10-year history (2.4 million total viewers) and its best demo rating in five years.

Elsewhere, going hour by hour….

8 pm |Survivor (9.8 mil/2.4) dropped 14 percent in the demo. The Great Pumpkin opened ABC’s night with 7.9 mil/2.7, though The Neighbors (5.8 mil/1.8) dropped the ball by shedding some 30 percent of that, down 17 and 10 percent week-to-week. Guys With Kids led out of 30 Rock with 3.8 mil/1.4, flat versus last Wednesday.

9 pm |Criminal Minds was Wednesday’s most watched program with 12 million total viewers, up a handful of eyeballs, while dipping two tenths in the demo (to 2.9). Modern Family (10.4 mil/4.1) drew the highest rating (though was down 16 percent), while Suburgatory (6.4 mil/2.4) slipped 13 and 11 percent. SVU (6.2 mil/1.7) was down 8 and 11 percent.